ROCKLAND — A Maine man convicted of killing his drug supplier for cutting him off is due to be sentenced.

Andrew Kierstead was convicted of murder in the September 2012 shotgun killing of Richard Mills outside Mills’ home in Cushing.

Prosecutors say the 41-year-old Kierstead told them he shot Mills because Mills had hooked him on drugs but then shut him off for not paying a drug debt. Experts testified during the trial that Kierstead shot Mills once and then followed him and continuing firing with a 12-gauge shotgun.

Kierstead’s lawyer argued for a manslaughter verdict, saying his client was too intoxicated and suffering from opiate addiction to have known what he was doing.